The readme for this hourly solar wind magnetic field data. The readme for this hourly solar wind magnetic field data. This data set was created at GSFC/SPDF in 2010 by taking averages over the 1-min magnetic field data at https://spdf.gsfc.nasa.gov/pub/data/imp/imp8/merged/. We used the solar wind flags in those records to build hourly averages for this data set only from 1-min values taken in the solar wind. Hours having more than half of their 1-min magnetic field values not in the solar wind did not have hourly averaged field values computed. The spacecraft position values (words 5-9), the field intensity (word 10) and the GSE and GSM cartesian components (words 14-18) were computed from corresponding 1-min values. Data for 00:00- 01:00 were used for the first hourly average of the day. Words 11-13 were computed from the hourly averaged GSE cartesian components. The number of points is the number of 1-min values (themselves averages) contributing to the hourly average. The sigma's (standard deviations) carry no memory of the sigma's in the 1-min averages. This data set has annual files of hourly IMP 8 magnetic field averages, in ASCII format. Every hour is represented; those for which there are no IMP solar wind data have fill values in their data words. ---------------------------------------------------- The words in each data record are: WORD FORMAT Fill Value MEANING UNITS/COMMENTS 1 I5 Year 1963, 1964, etc. 2 I4 Decimal Day January 1 = Day 1 3 I3 Hour 0, 1,...,23 4 I4 999 # of points in the IMF averages 5 F6.1 999.9 X, GSE (Re) 6 F6.1 999.9 Y, GSE (Re) 7 F6.1 999.9 Z, GSE (Re) 8 F6.1 999.9 Y, GSM (Re) 9 F6.1 999.9 Z, GSM (Re) 10 F6.1 999.9 Field Magnitude Average |B| 1/N SUM |B|, nT 11 F6.1 999.9 Magnitude of Average Field Vector sqrt(Bx^2+By^2+Bz^2) 12 F6.1 999.9 Lat.Angle of Aver. Field Vector Degrees (GSE coords) 13 F6.1 999.9 Long.Angle of Aver.Field Vector Degrees (GSE coords) 14 F6.1 999.9 Bx GSE, GSM nT 15 F6.1 999.9 By GSE nT 16 F6.1 999.9 Bz GSE nT 17 F6.1 999.9 By GSM nT 18 F6 1 999.9 Bz GSM nT 19 F6.1 999.9 sigma|B| RMS Standard Deviation in average magnitude (word 10), nT 20 F6.1 999.9 sigma B SQRT[sigma(Bx)**2 + Sigma(By)**2 + Sigma(Bz)**2], nT 21 F6.1 999.9 sigma Bx RMS Standard Deviation in GSE X-component average, nT 22 F6.1 999.9 sigma By RMS Standard Deviation in GSE Y-component average, nT 23 F6.1 999.9 sigma Bz RMS Standard Deviation in GSE Z-component average, nT -------------------------------------------------------------------------------- ----------------------------------------------------------------- Related data and directories: SPDF Data and Orbits Services ------------------------------------------------------------------- SPDF Contact: Natalia Papitashvili ------------------------------------------------------------- Please acknowledge NASA's Space Physics Data Facility and and relevant scientists identified above for data usage. -------------------------------------------------------- Authorizing NASA Official: Dr. R.E. McGuire, Head, SPDF, NASA Goddard Space Flight Center 301-286-7794, e-mail: Robert.E.McGuire@nasa.gov ------------------------------------------------------------------------- -----------------------------------------------------------------------